剑桥模型只适用于正常固结软黏土,不能描述不等向固结土的应力-应变行为的各向异性特性。基于剑桥模型,在其椭圆屈服面中引入各向异性张量和一个形状参数,建立了一个各向异性屈服面,提出了一个适用于等向和不等向固结软黏土的本构模型。各向异性张量的初始值由初始固结应力状态确定,其演化过程由一个与塑性剪应变和塑性体应变都有关的硬化法则描述。形状参数的引入保证了各向异性屈服面的灵活性和适应性。通过对Boston Blue黏土、高岭土和Otaniemi黏土的三轴试验结果的模拟,验证了模型的模拟能力。
The modified Cam-Clay model is only applicable for isotropically consolidated soft clay;and it cannot describe the anisotropic stress-strain behavior of anisotropically consolidated clay.A new model,which can be adopted for anisotropically consolidated soft clay,was developed here based on the modified Cam-Clay model.An anisotropic tensor and a shape parameter were introduced in the yield surface of the model.Initial value of the anisotropic tensor was determined by the initial consolidation stress state,and its evolution was described by a rotational hardening law both depending on plastic volumetric and deviatoric strain.The shape parameter enhanced the flexibility of the yield surface.Effectiveness of the model was verified by the triaxial experimental data of kaolin clay,boston Blue clay and Otaniemi clay.